Difficulties of Measuring

  • Vast Scale: Covers 71% of Earth’s surface, average depth 3,688m
  • Real-Time Monitoring: Difficulty transmitting data from deep or remote locations
  • Extreme conditions: Pressure, storms and salt require specialized equipment
  • Accessibility: Remote locations, harsh weather, high operational costs
  • Light Limitation: Optical methods only work in top ~200m

Satellite Observations

Note that it’s not possible to investigate the interior ocean with satellites

Satellite Observations

  • Advantages:
    • Global coverage and accessibility
    • Continuous monitoring of large areas
    • Cost-effective compared to ship-based surveys
  • Limitations:
    • Affected by atmospheric conditions
    • Cannot penetrate deep into the ocean

PACE Satellite (2024)

Light Attenuation in the Ocean

Light Attenuation in the Ocean

  • Remote sensing only observes top few meters of ocean
  • Cameras and optical instruments are ineffective at depth
  • Alternative methods required:
    • Cabled networks and instruments
    • Acoustic sensors
    • Resurfacing equipment

Observation Methods

HMS Challenger (1872-1876)

Ship-Based Measurements

  • CTD Casts: Conductivity, Temperature, and Depth profiling and water samples
  • Acoustic Doppler Current Profilers (ADCP): Measuring ocean currents
  • Multibeam Echosounders: High-resolution seafloor mapping
  • Sediment Cores: Extracting seafloor samples for geological and climate studies
  • Tows: Biological sampling of plankton and marine organisms

Benefits of CTD Measurements

  • High Vertical Resolution: Continuous profiling from surface to seafloor
  • Targeted Sampling: Niskin bottles collect water at specific depths of interest
  • Multiple Parameters: Temperature, salinity, depth, plus additional sensors (O₂, chlorophyll, turbidity)
  • Water Mass Identification: Characterize ocean layers and circulation patterns
  • Calibration Standard: Validates satellite and autonomous sensor data

Plankton measurements

  • Water Sampling
  • In-Situ Imaging
  • Chlorophyll Analysis
  • eDNA Filtering
  • Tows: nets or CPR

VirtualShip expedition

  • 9 days of ship time
  • Depart and arrive from Texel, Netherlands
  • Straight transect starting from the deep shelve
  • Inslingeren: (zeem.) opnieuw wennen aan het zeemansleven
  • Travel and CTD deployment time
  • SURF Research Cloud setup by Jamie
  • Instructions in Jupyter Notebook

VR and life @ sea